Yeah, that could be part of it, but currently I think gnucleus is the only one to do this.

It's a double-edged sword really. On the good side it keeps you form getting hammered by scores of people trying to download - a real problem when you've already got enough queued to keep busy for hours. When I used to use BearShare (a long, long time ago) I would disconnect from the network at night and have enough people pounding me that my uploads would still be busy the next morning!

All those retries eat up a ton of resources too. It would probably be better if it only stopped sending results once the number of download attempts hit a certain level maybe. Also the fact that most peers deperference busy servers in some way helps too. In fact, I wish Gnucleus had the "don't display busy servers" check box right on the front of every search window (along with a file type dropdown filter). I always find myself going into the preferences to switch it back and forth.